Bolt for a straight-pull bolt-action rifle

ABSTRACT

A breech for a straight-pull repeater rifle, comprising a breech box and a locking sleeve guided therein as well as a locking bar guided in the breech box and connected to the locking sleeve, the locking bar connects a bolt head to a bolt handle with a interposition of a chain link, wherein the chain link is linked in an articulated manner to the locking bar and the bolt handle, and the bolt handle can be swivelled between an open position and a closed position of the breech and interacts with a firing pin nut connected to a firing pin. A bolt head inserted into a breech sleeve at an end of the breech facing away from the bolt handle is provided. The locking sleeve and the locking bar are a one-part locking sleeve-bar and a locking spring pushing the chain link in the direction of its closed position is provided.

BACKGROUND OF THE INVENTION

The present invention relates to a breech for a straight-pull repeater, which comprises a breech box and a locking sleeve guided therein as well as a locking bar guided in the breech box and connected in one piece to the locking sleeve, which locking bar connects a bolt head facing a cartridge chamber to a bolt handle with the interposition of a chain link, wherein the chain link is linked in an articulated manner to the locking bar and the bolt handle, and the bolt handle can be swivelled between an open position and a closed position of the breech and interacts with a firing pin nut connected to a firing pin, and furthermore a bolt head which can be inserted into a breech sleeve at an end of the breech facing away from the bolt handle is provided, as well as the use thereof.

Breeches for firearms, in particular for straight-pull repeaters, are known in the most diverse designs, wherein irrespective of the type of design of the breech, the top priority is to make available a breech with which the risk of accidents can be minimised during firing and/or loading. The greatest danger is posed by unintended opening of the breech of the weapon during the use of the same, which is intended to be prevented by the design of a suitable breech and the provision of safety elements.

For such a minimisation of the risks, DE-A 2 418 915 describes a breech, in which the breech cylinder can be locked or fixed in the axial direction in a locking tube by radially splayable spring rings in the breech sleeve. The locking tube is fixed pivotably about the barrel axis in the breech sleeve by means of a thread and a recess is also constituted in the locking tube in the direction to the rifle stock, in which recess the bolt handle engages. When the bolt handle is swivelled about the barrel axis, the locking tube is rotated like a screw when the breech is closed, so that the breech cylinder abuts and is locked against the cartridge base.

A further design of a breech can be seen in EP-A 1 764 575, in which the breech on the one hand comprises a device, by means of which the bolt distance of the bolt head from the cartridge chamber can be regulated automatically and on the other hand comprises a bolt handle coupled with a locking bar, which bolt handle can be swivelled between an open and closed position and is arranged in its closed position, in such a way that a chain link fixed to the locking bar is held by the bolt handle in the closed position, and moreover is constituted such that a link constituted by the connection of the bolt handle to the chain link, at the end of the closing movement of the bolt handle in an axial direction, is arranged offset by a distance with respect to the axis of the locking bar. A drawback with this construction is that, due to the offset arrangement of the chain link in relation to the longitudinal axis of the locking bar, the hinged connection formed by the bolt handle and the chain link can inadvertently open the bolt handle and therefore the breech due to an action of a force in the axial direction of the breech. Due to such inadvertent opening of the bolt handle during a closing procedure, crucial risks emerge for the user from such a construction, since unintended opening of the bolt handle and therefore the rifle breech, for example due to misfiring or dual ignition of a cartridge, can lead not only to mechanical damage to the gun, but in particular to serious injuries to the user.

A breech for a straight-pull repeater is already known from EP 2 631 586 A2, in which the chain link is constituted as a straight chain link and is linked in a lateral recess of the bolt handle. By means of such a construction, it is made possible largely to prevent unintended swivelling of the bolt handle during the closing, but for a smooth functioning of this breech, however, a plurality of further elements such as spring-loaded wedges, snap-in noses and in particular a plurality of springs are required, which are intended to push the locking bar into a closed position, as a result of which the breech is overall constructed in a complicated manner. A drawback with such a construction is that the springs are overall too weak to be able to ensure, by a corresponding action in the direction of a closed position, that the breech is not inadvertently opened and moreover a very complicated structure of the breech is caused by the provision of a plurality of springs.

Finally, a breech for a straight-pull repeater has become known from EP 3 054 260 B1, in which the locking bar guided in a breech sleeve is connected to a bolt handle at its bolt head facing a cartridge chamber with the interposition of a straight chain link, wherein the chain link is linked to the bolt handle by means of a first swivel bearing and, by means of a second swivel bearing, is linked to the locking bar, and wherein the bolt handle can be swivelled about a third swivel bearing between an open and closed position. Finally, in this embodiment, a fourth swivel bearing at least partially penetrating the bolt handle is provided as well as a locking member surrounding the latter which, abutting against the free end of the locking bar arranged in the interior of the breech, is arranged forcibly pivotable by pivoting of the bolt handle.

The drawback with all these constructions is that they can be used precisely for a single calibre of a straight-pull repeater and that additional problems can also arise with regard to the safety of the straight-pull repeater, in particular with regard to unintended opening of the same or assembly of the same in an incorrect position.

SUMMARY OF THE INVENTION

The aim of the present invention is to make available a breech for a straight-pull repeater, which is even safer with regard to unintended opening of the breech due to the gas pressure occurring during the ignition of the propellant and, moreover, to adapt the breech in such a way that it can be used directly in different straight-pull repeaters, conventional repeaters and auto-loading rifles, in particular straight-pull repeaters, conventional repeaters and auto-loading rifles with a different calibre of the ammunition.

To solve this problem, the invention is essentially characterised in that the locking sleeve and the locking bar are constituted as a one-part locking sleeve-bar and that a locking spring surrounding the locking sleeve-bar and pushing the chain link in the direction of its closed position is provided. Due to the fact that the breech is constituted in such a way that the locking sleeve and the locking bar are constituted as a one-part locking sleeve-bar, greater rigidity of the locking sleeve-bar is achieved compared to the variant of the locking sleeve and locking bar constituted in two parts, which also leads to greater precision of the breech. Furthermore, because the locking sleeve-bar is surrounded by a locking spring, which pushes the chain link in the direction to its closed position, unintended opening of the breech is made more difficult. In contrast with conventional variants of a locking bar, to which a plurality of small, in particular weak, locking springs were linked, the embodiment according to the present invention is not only significantly simpler structurally, but surprisingly it is possible to arrange a strong spring in the small available space in the interior of the locking sleeve, which pushes the chain link so hard in the direction of its closed position, that unintended opening of the breech at all events is prevented. With such a recoil spring surrounding the locking sleeve-bar, automatic locking of the bolt in the breech sleeve is brought about, brought about particularly when the breech sleeve is arranged correctly in the breech box.

According to a development of the invention, the breech is constituted such that a stop element for the locking spring comprising at least one pressure release slot is also provided on the locking sleeve-bar. Due to the fact that a stop element for the locking spring comprising at least one pressure release slot is provided on the locking sleeve-bar, it is on the one hand ensured that the locking spring is kept securely in position on the locking sleeve-bar and on the other hand it is guaranteed that high pressures occurring during the shot in the interior of the breech can be securely and reliably diverted and cannot bring about unintended opening of the breech on account of a high build-up of pressures.

According to a development of the invention, the breech here is constituted in such a way that the stop element comprises a plurality of preferably three pressure release slots, which are constituted as flat areas on the stop element which are spaced uniformly apart from one another. Due to the fact that the stop element is constituted with preferably three pressure release slots, which pressure release slots constitute flat areas on the stop element spaced uniformly apart from one another, it is on the one hand ensured that 100% uniform distribution of the weight is provided in the interior of the breech and on the other hand, by means of such an embodiment of the stop element, apart from a secure pressure release of the breech, the latter can be engaged directly for example by tools and can be held in position, which is advantageous for example during assembly or replacement of parts.

According to a development of the invention, the breech is constituted such that the chain link is connected in an articulated manner both to the bolt handle and also the locking sleeve-bar by means of a hinged connection, as a result of which, through the provision of the swivel bearing via which the chain link is connected both to the bolt handle and also to the locking sleeve-bar, it becomes possible to provide a further simplification of the construction and in particular it is possible to prevent an unintended opening or closing of the breech with such a chain link provided with a swivel bearing.

As corresponds to a development of the invention, by the fact that the breech is constituted in such a way that in a closed position of the breech a longitudinal axis of the locking sleeve-bar encloses an angle of ≤0° with an axis running through centre points of an articulated connection between bolt holder and locking sleeve-bar, a further safety measure against unintentional opening of the bolt holder by a force acting in the axial direction of the rifle is reliably prevented. This is particularly the case since a centre line of the articulated axis of the chain link in such a case cannot lie exactly over the longitudinal axis of the firearm, but is swivelled out over the dead-centre point, which would lie exactly over the longitudinal axis of the firearm, and in particular is swivelled by an angle of ≤0°. As a result of this swivelling beyond the convergence of the axes, i.e. beyond a dead-centre point, an unintentional opening of the breech becomes even more difficult and can only be achieved by intentional manual actuation of the bolt handle.

According to a development of the invention, the breech is constituted such that the locking sleeve-bar with the fitted bolt head and at least two, preferably four clamping jaws is locked with a closing spring surrounding the locking sleeve-bar in the breech box. By means of such an embodiment of the breech, greater stability of the entire system, in particular of the unit breech box and locking sleeve-bar, is provided. Furthermore, if the spring-loaded clamping jaws are provided with a width that is enlarged compared to conventional holders, the guide length between the breech and the bolt head is enlarged at the same time, and not only is a higher stability of the overall system achieved, but also greater precision of the straight-pull repeater during shooting, since the possibilities of movement of the locking sleeve-bar in the breech box are minimised or largely prevented. The enlarged guide length also enables the use of a wider locking lever, which in turn prevents an undesired shearing of the bolt head.

According to a development of the invention, the breech is constituted such that the locking sleeve-bar encloses an angle with a longitudinal axis of the breech of ≤4°, preferably an angle in the range between 3° and 4°. Since the locking sleeve-bar encloses an angle with the longitudinal axis of the breech of ≤4°, preferably in the range between 3° and 4°, it is ensured that the displacement of the locking sleeve-bar backwards can be prevented and in particular, by means of such an embodiment, the force which is required for unintended opening of the breech is increased still further. In particular, such an embodiment thus makes it possible for the spring-loaded clamping jaws, which hold the locking sleeve-bar in the breech box, to hold the locking sleeve-bar inclined in a locked state in the interior of the breech box by an angle diverging from 0° and thus further to prevent an unintended opening of the breech. It should be stated in this connection that the ideal state, i.e. the state in which an unintended opening of the breech is prevented with certainty, would be an angle of 0°, which the locking sleeve-bar encloses with the longitudinal axis of the breech, which however would in turn mean that infinitely great forces were required for opening of the bolt holder and thus an angle is to be selected in practice which exceeds 0° as little as possible and nonetheless offers sufficient safety against unintentional opening. Merely for the sake of good order, it is stated that an angle of approximately 6° was common for example in the prior art and the experts in the field were or are of the conviction that a further reduction of the angle would make the breech unmanageable.

According to a development of the invention, the breech is constituted such that different bolt heads with different calibres from one another can be arranged in the breech box in cooperation with the locking sleeve-bar. With such an embodiment, a modular structure of the straight-pull repeater can be achieved, i.e. in particular it is possible to adapt one and the same breech box to a plurality of different calibres, whereby the locking sleeve-bar is provided with corresponding bolt heads of different calibre. It goes without saying that all the other parts of such a straight-pull repeater are constituted such that they have standardised threads, replaceable parts, such as for example a trigger, recoil plates, magazine holders or suchlike, which can be adapted to the respective calibre of the ammunition to be fired. On account of the special construction of the breech according to the invention, the overall breech can be adapted to a plurality of different calibres.

Furthermore, due to the fact that the breech box is provided with a spring-loaded push-in lock at its end incorporating the bolt head, it is ensured that the breech, in particular the locking sleeve-bar, cannot be used in the breech box without the appropriate bolt head in the breech box or conversely only a bolt head, which is correspondingly connected to the locking sleeve-bar, is used in the breech box. The spring-loaded push-in lock in this case prevents a further insertion of the sliding lock-bar or completely prevents the use of the bolt head alone, so that only correctly assembled parts of the breech can be used and a further safety factor for prevention of unintentional actuation or triggering and an incorrect assembly of the breech is thus provided.

A breech according to the present invention is particularly well suited for the use of ammunition calibres different from one another and can therefore, unlike the case with known straight-pull repeaters, be adapted to ammunition of any calibre merely by exchanging the bolt head and the associated barrel. Due to the fact that all the parts of the breech are constituted such that they can be assembled without conversion of those parts, the size of which depends on the calibre of the ammunition to be fired, such as for example the diameter of the barrel, it is surprisingly possible to provide a breech for a straight-pull repeater that is suitable for the most diverse uses. As is known, it is possible with a straight-pull repeater to provide a firing speed that almost corresponds to that of a semi-automatic weapon, but furthermore it is possible with the breech according to the present invention to provide an extremely high degree of safety despite these high possible firing speeds, since the breech is provided and secured with a plurality of safety elements against any unintended opening. Surprisingly, the breech was able to be constituted and in particular verified, despite the provision of a plurality of safety elements, that it can be adapted to the most varied ammunition calibres without cruder conversion measures and can be provided with barrels which are adapted to the given ammunition calibres, wherein it is possible, unlike with traditional straight-pull repeaters, to adapt one and the same rifle to the most diverse ammunition calibres and thus for the most diverse uses.

DESCRIPTION OF THE DRAWINGS

The invention is explained in greater detail below with the aid of examples of embodiment represented in the drawing. The latter show:

FIG. 1 a view of the breech according to the invention in partial cross-section,

FIG. 2 a partial view of a breech from FIG. 1 in a closed position,

FIG. 3 a partial view of the breech similar to FIG. 2 in an open position of the breech,

FIG. 4 a cross-section through the end region of the locking sleeve-bar with the bolt head in a locked position, and

FIG. 5 a similar view of the end region of the locking sleeve-bar in an unlocked position,

FIG. 6 a partial view of a front end region of the breech with placed-on bolt head and locked push-in lock

FIG. 7 a detailed view which shows breech sleeve and bolt head.

DETAILED DESCRPTION OF THE INVENTION

FIG. 1 shows a partial view of the breech according to the invention, in which in particular elements such as the bolt head, a trigger and suchlike, which in the first place are not essential for a simplified representation of the embodiment according to the invention, are not represented.

In FIG. 1 , a breech sleeve is denoted by 8, in the interior of which a locking sleeve-bar 9 is guided, the end of which facing away from a barrel is connected to a bolt handle 4 with the interposition of a chain link 5. Bolt handle 4 is mounted pivotably between an open and closed position, wherein the uncocked breech is shown in FIG. 1 . Bolt handle 4 also cooperates with a firing pin 6 and a firing pin nut 7. Bolt handle 4 can be swivelled about a swivel point 19 and can be transferred from the shown position into a cocked position. During cocking and thus movement of bolt handle 4 in the direction of arrow 17, the movement of a roller 20 along an inclined face of firing pin nut 7 as well as a tensile stress of chain link 5 and a deflection of the same out of the position essentially aligned with locking sleeve-bar 9 through swivelling via a second swivel point 21 between chain link 5 and bolt handle 4 continue to follow. Both firing pin 6 and also chain link 5 are coupled with locking sleeve-bar 9, which locking sleeve-bar 9 is constituted in one piece, i.e. unlike embodiments according to the prior art, in which the locking sleeve-bars are in two parts, i.e. as a separate locking bar and locking sleeve, locking sleeve-bar 9 is constituted as a single part, wherein a holding element 22 is arranged on the part of locking sleeve-bar 9 which is facing the bolt handle 4. A locking spring 10 surrounds locking sleeve-bar 9 and is subjected to pressure in the position represented in FIG. 1 , in that locking spring 10 is supported and becomes compressed on holding element 22 surrounding the locking sleeve-bar at least in the region of the end of locking spring 10. At the end of locking spring 10 facing away from holding element 22, it abuts against a stop element 12 located on locking sleeve-bar 9. Stop element 12 is constructed such that it comprises a plurality of flat areas, which act as pressure release slots 11. Pressure release slots 11 prevent a pressure built up in the interior of breech 1 from leading to a malfunction of breech 1 and prevent the build-up of an excessively high pressure in the interior of breech 1.

Furthermore, striking pin spring 28 is guided and held in the interior of holding element 22 constituted elongated and surrounding the locking sleeve-bar.

FIG. 2 represents the uncocked state of breech 1 and it can clearly be seen from this FIG. 2 that chain link 5 is arranged in such a way that its longitudinal axis does not lie 100% over the longitudinal axis of locking sleeve-bar 9, but encloses with the latter an angle α of approximately 0.01°. As a result of this small angle, chain link 5 in the closed position of bolt handle 4 is swivelled such that it is swivelled over the dead-centre position, which would be achieved with a 100% alignment of the two axes, so that departure of chain link 5 from its locking position can only take place by the application of a force in the direction of arrow 23 and in particular if this force acts on the swivel point between bolt handle 4 and chain link 5.

In FIG. 3 , which represents the cocked position of bolt handle 4 and thus of breech 1, it can on the one hand be seen that, by the swivelling of bolt handle 4 in the opened position, chain link 5 is pulled over the second swivel point 21 out of its dead-centre position and at the same time roller 20 of bolt handle 4 slides over the inclined face of firing pin nut 7. With this swivelling movement of bolt handle 4, the firing pin interacting with firing pin nut 7, not visible in the figure, is subjected to pressure and at the same time locking spring 10 of locking sleeve-bar 9, not shown in FIG. 3 , is subjected to traction. If an unintended triggering of firing pin 6 occurs during a movement of bolt handle 4 and thus of breech 1 before the movement into the position of FIG. 2 is complete, the energy released by firing pin 6 is directly transmitted through firing pin nut 7 onto roller 20 and through the special structural embodiment of bolt handle 4, firing pin nut 7 will enter into the recess of bolt handle 4 provided for the purpose and automatically close the breech. As a result of this automatic closing of the breech, unintendedly released firing energy is completely removed and ignition of the firearm is prevented.

In FIGS. 4 and 5 , which show the region of the breech that is directed towards the cartridge chamber, the reference numbers are retained as far as possible and FIG. 4 shows the locked state of locking sleeve-bar 9 in breech box 2 and FIG. 5 the unlocked state of locking sleeve-bar 9 in breech box 2. In the locked state of locking sleeve-bar 9, locking sleeve-bar 9 is held by at least two clamping jaws 14, in particular spring-loaded clamping jaws, which are arranged in breech box 2 in such a way that they are splayed radially by 4°, as a result of which locking sleeve-bar 9 is held in the interior of the breech box by splayed clamping jaws 14. By this arrangement of locking sleeve-bar 9 in breech box 2, a further safety feature is provided, with which an unintentional opening of the breech can be prevented. Clamping jaws 14 are correspondingly applied differently here. It can also be seen from FIG. 4 that, in the locked state of locking sleeve-bar 9, the latter is gripped by clamping jaws 14 and locking sleeve-bar 9 interacts with bolt head 3. In the unlocked state, locking sleeve-bar 9 is pulled back on account of the swivelling of bolt handle 4 described in FIGS. 1 to 3 and the traction effect thus exerted on locking sleeve-bar 9 via chain link 5, and neither of locking jaws 14 is engaged in this position with locking sleeve-bar 9 and the latter is thus not arranged in the splayed position in the interior of breech box 2, but rather its longitudinal axis coincides with the longitudinal axis of breech box 2. Locking sleeve-bar 9 is not engaged here with bolt head 3.

FIG. 6 represents a further safety feature of breech 1 according to the invention, according to which an introduction of breech 1 without bolt head 3 as well as an introduction of bolt head 3 into breech box 2 without correct connection to locking sleeve-bar 9 is prevented. This safety feature in this connection is a spring loaded push-in lock 18, which at all events prevents insertion of locking sleeve-bar 9 without bolt head 3 or insertion of bolt head 3 alone in breech box 2 and therefore a connection with the cartridge chamber (not represented). Only with correct positioning and correct connection of bolt head 3 with locking sleeve-bar 9 is insertion of these elements and locking of the same in breech box 2 possible with the aid of push-in lock 18, the locking spring of which is denoted by 24.

FIG. 7 shows a detail view, which shows correct positioning of a locking sleeve 9 with bolt head 3. For this purpose, locking sleeve-bar 9 on the one hand comprises a thorn-shaped extension, which fits exactly into a corresponding opening of bolt head 3. Furthermore, a guide pin 25 is provided on breech sleeve 8, which can engage in a corresponding recess 26 of bolt head 3, in order to ensure exact positioning of breech sleeve 8 in relation to bolt head 3. Further locking elements 27 are provided on bolt head 3 for locking of breech sleeve 8 with bolt head 3.

Furthermore, the breech of the straight-pull repeater can additionally comprise all the safety features which straight-pull repeaters comprise. Thus, for example, on account of the symmetrical embodiment of the entire breech, a bolt catch can be mounted both on the right and on the left and the breech can be suitably used without conversion for right-handers and left-handers. 

1. A breech for a straight-pull repeater rifle, which comprises a breech box and a locking sleeve guided therein as well as a locking bar guided in the breech box and connected in one piece to the locking sleeve, the locking bar connects a bolt head facing a cartridge chamber to a bolt handle with the interposition of a chain link, wherein the chain link is linked in an articulated manner to the locking bar and the bolt handle, and the bolt handle is swivelled between an open position and a closed position of the breech and interacts with a firing pin nut connected to a firing pin, and a bolt head is inserted into a breech sleeve at an end of the breech facing away from the bolt handle, wherein the locking sleeve and the locking bar are made as a one-part locking sleeve-bar and a locking spring surrounding the locking sleeve-bar pushes the chain link in the direction of its closed position.
 2. The breech according to claim 1, wherein a stop element for the locking spring comprising at least one pressure release slot is provided on the locking sleeve-bar.
 3. The breech according to claim 2, wherein the stop element comprises a plurality of three pressure release slots, which are flat areas on the stop element and spaced uniformly apart from one another.
 4. The breech according to claim 1, wherein the chain link is connected in an articulated manner to both the bolt handle and the locking sleeve-bar by means of a hinged connection.
 5. The breech according to claim 1 wherein in closed position of the breech a longitudinal axis of the locking sleeve-bar encloses an angle of ≤0° with an axis running through centre points of an articulated connection between bolt handle and the locking sleeve-bar.
 6. The breech according to claim 1, wherein the locking sleeve-bar with the bolt head and at least two clamping jaws are locked with a locking spring surrounding the locking sleeve-bar in the breech box.
 7. The breech according to claim 1, wherein the locking sleeve-bar encloses an angle with a longitudinal axis of the breech of ≤4°.
 8. The breech according to claim 1, wherein different bolt heads with different calibres from one another can be arranged in the breech sleeve in cooperation with the locking sleeve-bar.
 9. The breech according to claim 1, wherein the breech box is provided with a spring-loaded push-in lock at its end incorporating the bolt head.
 10. The use of a breech for a straight-pull repeater rifle according to claim 1, in a straight-pull repeater rifle which can be used with ammunition calibres and barrel inner diameters different from one another. 